This application relates to the art of heat exchangers and, more particularly, to heat exchangers for use with space heaters which burn solid fuel such as wood or coal. Although the invention is particularly applicable to stoves which burn solid fuel and will be described with particular reference thereto, it will be appreciated that the invention has broader aspects and the heat exchanger can be used with space heaters such as fireplaces, and with space heaters which do not burn solid fuel.
Space heaters which burn solid fuel, such as wood or coal, have become very popular due to the shortage and high cost of natural gas, propane and fuel oil. Such space heaters, and particularly stoves, are finding high acceptance for residential and small commercial heating requirements. Although space heaters of this type are quite efficient and are easily capable of comfortably heating a large room in which they are installed, the heat is too often not uniformly distributed in the room, and is not readily distributed to other rooms. Many arrangements have been proposed for utilizing more of the heat output from such heat exchangers by heating remote areas or heating water, or both. However, previous arrangements of this type have been very complicated and expensive. In arrangements for circulating water through the space heater for heating the water and extracting heat therefrom at a remote location, coiled pipes and the like have been used for water circulation. Creosote and other combustion products form deposits on the pipe coils, and greatly reduce the heat transfer efficiency thereof. These deposits are very difficult to clean from round pipes. Furthermore, manufacture and assembly of coiled pipes and other similar radiators make such heat exchangers very expensive to manufacture and assemble. This is particularly true where the heat exchanger assembly requires a large number of individual pipes and joints which must be leak proof. Water circulating heat exchangers of this type are not usually suitable for installation in existing space heaters which were not build for that purpose.
It would be desirable to have a water circulating heat exchanger which could be installed in existing space heater structures or used in specially designed space heater structures, while being relatively inexpensive to manufacture and install.